Continuous Production of Biodiesel via Supercritical Methanol Transesterification in a Tubular Reactor. Part 1: Thermophysical and Transitive Properties of Supercritical Methanol

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• 作者：Wen Chen ; Cunwen Wang ; Weiyong Ying ; Weiguo Wang ; Yuanxin Wu ; Junfeng Zhang
• 刊名：Energy & Fuels
• 出版年：2009
• 出版时间：January 22, 2009
• 年：2009
• 卷：23
• 期：1
• 页码：526-532
• 全文大小：250K
• 年卷期：v.23,no.1(January 22, 2009)
• ISSN：1520-5029

文摘

In the range of 520−600 K and 100−400 bar, the thermophysical properties of supercritical methanol, which includes density ρ, viscosity η, isobaric heat capacity C_P, and coefficient of thermal conductivity λ, are calculated according to different methods and the effect of temperature and pressure is also discussed. On the basis of the thermophysical properties, the transitive properties of supercritical methanol flowing in a 6 × 1.5 mm round tube, which includes the Reynolds number Re, the Prandtl number Pr, and the film coefficient of heat transfer α, are calculated and the change laws of them with temperature, pressure, and velocity are also illustrated. It is shown that all ρ, η, C_p, λ, Re, Pr, and α decrease with the increase of the temperature at constant pressure, but their changing trend is not consistent with the pressure increasing at a constant temperature. ρ, η, and λ always increase as the pressure increases. C_P, Re, and Pr decrease consistently at 520−540 K and increase first and then decrease at 540−600 K. For α, with the increase of pressure, it almost remains stable at 520 K and first increases sharply and then decreases slowly at 530−570 K, but at 580−600 K, it always goes up from the beginning from 100 to 400 bar.